A V-band sub-harmonic mixer with an integrated frequency doubler and a 180o out-of-phase splitter using standard 0.13 μm CMOS technology is reported. The sub-harmonic mixer comprises a current-reused bleeding mixer, a baseband amplifier, a 180° (Wilkinson-power-divider-based) out-of-phase splitter, and a frequency doubler. The mixer consumed 31.5 mW and achieved input return loss at RF port better than -10 dB for frequencies from 49.8 GHz to 63 GHz. At IF of 20 MHz, the mixer achieved maximum conversion gain of 9.5 dB at RF of 53 GHz. The corresponding 3-dB bandwidth (ω3db) of RF is 9.6 GHz (48.4 ~ 58 GHz). The measured LO-to-RF and LO-to-IF isolation were better than -50 dB over the frequency band of interest. In addition, the measured input 1-dB compression point (P1dB) and input third-order inter-modulation point (IIP3) were -8 dBm and 2.2 dBm, respectively, at RF of 60 GHz. These results demonstrate the proposed mixer architecture is very promising for high- performance V-band RFIC applications.